Shot Peening Time Effect on Corrosion Behaviors of Al Alloy 2024-T3

Abstract

In this study many specimen s were prepared from 2024-T3 Aluminum alloy for corrosion test by the dimensions of (15*15*3) mm according to ASTM G71-31 and then subjected to shot peening process at different time (15, 30, 45) minutes using steel ball having a diameter of 2.75 mm and Rockwell Hardness of 55RC to induce compressive residual stress which were measured using X-Ray diffraction method, surface roughness and hardness were tested before and after peening. Electrochemical corrosion test by Tafel extrapolation method was carried out in an environment of 3 .5% NaCl solutions (sea water) where Corrosion rate calculated using Tafle equation. The obtained results show a favorable influence of SP treatment on improving corrosion resistance as induced compressive residual stresses and hardened surface layer, the best corrosion resistance was at SP time of 30 minutes since compressive stress was the highest.

Keywords

• aluminum
• shot peening
• surface roughness
• residual stresses
• corrosion resistance